Evaluating land degradation processes to derive unified land degradation mitigation strategies for river basins of Ethiopia

Abstract

Land degradation is associated with multiple simultaneous processes and causes serious socioenvironmental problems in sub-Saharan countries where it remains less understood but is already under precarious conditions. In this study, previous reports on land degradation are assessed, and an analysis of the land degradation process in Ethiopia's five basins is presented. The complex pattern of spatially interacting processes is explored, emphasizing the three combinations of land degradation pathways across subbasin and basin lands mapped and analyzed in the QGIS. The land degradation index (LDI) revealed that the Awash, Tekezze, and Abbay basins are the most affected ones, constituting 65%, 18%, and 12%, respectively, of the five basins, respectively. Additionally, the Tekezze (~ 8.41 Mha), Abbay (~ 17.46 Mha), and Awash (~ 10.70 Mha) basins are impacted by slight to extreme degradation. The Omo-Gibe basin (0.067 Mha) is the least affected, alongside the Rift Valley basin. In the subbasins, extreme degradation is found in the Easter catchment (1.67 Mha) and the Tserare (0.22 Mha) subbasins in the Awash and Tekezze basins, respectively. The findings can aid land managers in developing strategies for mitigation and establishing baseline indicators for assessing composite impacts. Addressing other degradation processes such as soil nutrient and ground water decline will contribute to the development of land degradation mitigation strategies in the basins.

Keywords: Index; Soil acidity; Vegetation degradation; Water erosion.